Matthew Torres, Michael Kessens, Pierrelena Amazon, and Hassan Hussein, left to right, listen as President Barack Obama speaks during a rally for Hillary Clinton and democrats at Florida International University Arena on Thursday, Nov. 3, 2016. (Al Diaz/Miami Herald via AP)

WASHINGTON (AP) — While rules vary from state to state, in general poll watchers are registered voters appointed by the campaigns to sit in polling places and observe, pointing out potential problems to election officials and, in some states, challenge whether a person is actually eligible to vote. They cannot campaign or intimidate or confront voters directly, but they are generally the only non-election officials permitted to remain inside, or even near, a polling place.

Poll watchers have long been part of American elections, but they gained prominence this year as Republican candidate Donald Trump said he would recruit an army of volunteers to make sure the election wasn’t rigged. An Associated Press survey of election officials suggests that effort has fallen short.

— Most states say poll watchers cannot be candidates or, often, their spouses or close relatives. Police officers are banned in some states.

— In most states, candidates must register their poll watchers in advance.

— There is usually a limit on the number of poll watchers a candidate can appoint per precinct, often between one and three.

— Many states require poll watchers to wear a badge identifying themselves and their candidate or cause.

Some states have unusual rules:

— Kansas allows poll watchers as young as 14.

— Louisiana allows each candidate to appoint one “super watcher” who can visit any polling site where the candidate is listed in addition to regular poll watchers.

— Massachusetts has no qualifications or limitations beyond saying watchers cannot disrupt voter access or be disorderly. Wisconsin is similar except that it bans candidates and requires watchers to sign a log.